The invention relates to an extruder for synthetic materials with at least two mixing and conveying worms, comprising an extruder housing, an extruder inlet, a driving member for driving one of the worms and a gearing for driving the second worm.
Such extruders are known per se. In these known extruders the shaft of a first mixing and conveying worm is directly driven, while a gear wheel mounted on the shaft of the first mixing and conveying worm drives a gear wheel co-operating therewith and mounted on the driving shaft of the second mixing and conveying worm.
Such a drive suffers from the disadvantage that the two shafts of the mixing and conveying worms are strongly exposed to a bending load.